Correlating perimetric indices with three nerve fiber layer thickness measures

Area of Science:

• Ophthalmology
• Glaucoma Research
• Diagnostic Imaging

Background:

• Glaucoma diagnosis and monitoring rely on assessing retinal nerve fiber layer thickness (RNFLT) and visual field sensitivity.
• Standard automated perimetry (SAP) is a key functional test, while optical coherence tomography (OCT) and other imaging modalities estimate RNFLT.

Purpose of the Study:

• To compare the correlation between three different RNFLT estimation methods and visual field sensitivity measured by SAP.
• To identify the most accurate RNFLT measurement technique for predicting functional vision loss in glaucoma.

Main Methods:

• 400 eyes from 209 participants with glaucoma or high-risk status were analyzed.
• RNFLT was measured using spectral domain optical coherence tomography (SDOCT), scanning laser polarimetry (SLP), and confocal scanning laser tomography (CSLT).
• Visual field sensitivity was assessed using SAP, with linearized mean deviation (MD), mean sensitivity (MS), and pattern standard deviation (PSD) calculated.

Main Results:

• Linearized MS showed the strongest correlation with SDOCT-derived RNFLT (r = 0.57), followed by SLP (r = 0.40) and CSLT (r = 0.13).
• SDOCT consistently predicted MS(Lin) in multivariate models, while CSLT did not.
• Similar predictive trends favoring SDOCT were observed for MD(Lin) and PSD(Lin).

Conclusions:

• Average RNFLT estimated by SDOCT is a significantly better predictor of SAP status compared to SLP and CSLT.
• SDOCT measurements provide more reliable functional predictions for glaucoma patients.